Method of making shallow baking plates of cellulose material



Sept. .3, 1946. H. F. WATERS 2,407,118 I METHOD OF MAKING SHALLQW BAKING PLATES OF CELLULOSE MATERIAL Original Filed Aug 15, 1940 INVNTOR; BY HERB) F. WATERS a 72011? HTTORNEY Patented Sept. 3, 1946 UNITED STATES: PATENT OFFICE METHOD OFMAKING SHAIZIJOW BAKING PLATESOFCELLULOSE MATERIAL Harry FrWaters, New York, N. Y.

Original applicationAugust 15, 1940; Serial No. 352;679. Divid'ell and this application-April 20', 1 9 42, .Serial No; 439,638

2.Cl'aims.. 1

The present invention. relates to a: method of making shallowcooking and bakingutensils and; moneparticul-arly, to-a baking: pan of novel. and improved character. r

This application is: a division of my; application.

Serial No; 352-,6fl9,,filed-. August 15 1940:,- for Baking utensil;

Asthose. skilled in the art know, heretofore pans, dishes and similar-receptacles constituted of metal were used for baking pies, cakes; and similar bakery products. Whenmanuf'acturing and distributing pies; andother products of the describedcharacteron a commercial scale; it was customary tense the metal pans in which" the pie or cake wasbakedlfor delivering-the'product therein. Due .to thefact-that these metallic pans. were rather. expensive, it. wastnecessary to return the. pans to the baker atterthe baked-productlwas soldl Of. course, thisnecessitated returning a large number of'heavy metal; trays-or pans to.- the baker and cleaning and sterilizing. the same. prior to their repeated usewhich. involved.inconven ience. and expense. ,It. wasalready suggested to employ pans or trays constituted-o:f=.pulp, cardboard, or some other fibrous cellulosic. product and to transfer thepie. or. cake from the metal pan in which. it.was baked .ontosuch. receptacles. These paperor cardboard receptacles were generally cheap enough to be discarded after aisingle use, However, transfer. of variouspies, particu-- larly those containing fruit and. having a. relatively soft or fragile structure, involved difiicnlties, and the pie or other bakery product thustransferred didnot. offer the. same. attractive appearance'as those sold'inthep-ans.inwhich they were baked. Moreover, such transfer of the pie from one'receptacle into another required a considerable amountof labor. andhad. to be executed with great care.

Another suggestion for solvingthe outstanding problem involved the application of. baking utensils whichwhile sufliciently resistant to heat to permit baking of the .pie or cake therein, were inexpensive. enough to be used only once. Such bakingpans or. trays were described,- forexample, in U. S. Patent 206,099 to Fisher. The Fisher baking pancomprises a compound sheet obtained by facing asheet of. paper. withla second sheet of thin,.soft andpliable material; such as a metallic foil; This compound sheet was converted into a pamshapedarticle by means. of suitable dies. The dish. thus made-retained the fruit fluids or similar fluids constituting the product to be baked Without softening under their action. even when highlyheated: The lining or.- facing of; foil'pre-r Stuart in his Patents Nos. 2,027,296-and 2;170;O40

Which.is likewise produced from a foil-coated cellulosic material by means of. pressure'drawing operations. While the baking pans of the Fishertype could effectively resistrbaking: and-cocking temperatures and were-inexpensive enough, great difficulties were experienced inmanufacturing. them'on: apractical. and-commercial scale. The principal reason for these difficulties was thattheunavoidable; drawing operations employed; in

-; making. the pans or. dishes from fiat stock would expose the material to substantial drawing and: stretching stresses. This would break down the structureof the material andwas particularly injurious to the extremely thin andweakmetallic foil covering at leastthe inner surface thereof.

The metallic foil would break andv crack and would cause discontinuities of the protective layer between the pie and the paper pan through which. the semi-liquidconstituents ofthe piecould leak i into-thepaper. Of coursepthis was detrimental tothe'quality of the finishedproduct, In addition, the drawing operation employed in manufacturing. these. pans. Would-cause the production of wrinkles. on the inner surface of the. pane These wrinkles. were. not only objectionable from the. point of View ofappearance of the panbut also causedstrong adherence. of the baked product to. the panso that the pie. or cake couldbe removed only with difficulty andwould break. or crumble duringremoval. Although various other proposals andsuggestions were made to solve the outstanding problem and to. providethe art with a. completely satisfactory, simple,v attractive. and inexpensive, single-use baking pan,.none, as far as I am aware, of these suggestions and proposals. was completely satisfactory and successful when carried into practice on a practical and commercial scale. r

I have discovered a simple and completely satisfactory solution of the outstanding problem;

It is an object of the present invention to provide a method of making a single-use baking pan which eliminates the disadvantages and imperfections of prior products.

It is another object of the present invention to provide a method of making a baking pan of novel and improved character which is constituted of a fibrous cellulosic. material and which isin all respectsequaf or superior to conventional metal bakingpans.

It is a further object of the present invention to provide a method of making a baking pan for baking pies, cakes and similar bakery products which is integrally formed of a single sheet of cellulosic material by means of folding operations.

It is also within the contemplation of the invention to provide a method of making a baking or cooking utensil formed from sheet-like cellulosic material by means of folding operations which is constituted of plane and smooth walls at least on the inner surface thereof and is free from wrinkles and other detrimental irregularities of surface.

The invention also contemplates a method of making a baking utensil constituted of cellulosic sheet material, laminated with metallic foil which is extremely simple in structure, satisfactory in operation and sufficiently low in cost to be discarded after a single use.

Other and further objects and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawing in which:

Fig. 1 illustrates a plan view of a blank for forming a preferred embodiment of the cooking utensil of the invention;

Fig. 2 depicts a perspective view of the finished cooking or baking utensil;

Fig. 3 is a fragmentary sectional view taken on line 3--3 of Fig. 2, the thickness of the layers therein being greatly exaggerated for clarity of illustration Fig. 4 shows an enlarged and fragmentary perspective view of the underside of one of the pleats incorporated into the utensil of the invention; and

Fig. 5 is a plan view of fragmentary character of a portion of a blank forming a modified embodiment of the present invention.

Broadly stated, according to the principles of my invention, I completely abandon and discard all prior concepts and procedures heretofore employed in the manufacture of single-use cellulosic baking pans. While all of these prior attempts for the production of baking pans from cellulosic materials involved a close imitation of the curved and circular shape of conventional metallic baking pans, I have discovered that practically all of the difficulties encountered in the manufacture of pans of the described character may be eliminated by dispensing with curved surfaces in the pan. Thus, I have found that an integral and sheet-like blank of cardboard or pasteboard may be converted into a satisfactory baking pan exclusively by means of scoring and folding operations. A regular polygonal shape has been found especially advantageous. Accordingly, a preferred embodiment of my invention comprises a bottom wall of polygonal shape, upwardly sloping side walls surrounding said bottom wall and a marginal or top flange. I have discovered that such polygon-shaped pans may be formed by means of folding operations from an integral sheet, such folding operations being greatly facilitated by the previous provision of score lines in suitable configuration. This folding operation will cause the production of excess material in the corners of the polygonal side walls and this excess material may be taken up by means of suitable pleats which at the same time Provide additional reinforcement of the finished product. A suitable heat-resistant adhesive, staples, and the like fastening elements may be employed to hold said pleats together and to maintain the finished product in its desired shape.

Great variations are possible in the materials employed for making the baking pans of the invention. Generally spe n o t good qua ity cellulosic boards such as virgin board, ground wood board, etc., are satisfactory and capable of resisting baking temperatures. In some cases it may be advisable to add small amounts of fireproofing agents such as fire clay, certain silicates and the like for further improving the heat resistant properties of the cellulosic board. In addition, it is in most cases desirable to cover or to coat at least the inner surface of the pan with a suitable coating or laminating material in order to prevent direct contact between the article to be baked and the cellulosic body of the pan. Preferred materials for this purpose are especially aluminum foil as this is suggested in the Fisher patent, but also certain synthetic resins of a sufficiently high melting point which may be applied to such surface in the form of a layer or lamination or in the form of a coating. Those skilled in the art of resins have no difiiculty in selecting such coating or laminating materials keeping in mind that such materials must have a melting point over 400 F., must not be injurious to health and. must not possess any objectionable odor. Examples of such materials are vinyl resins, cellulose acetate, and the like.

A similar coating or lamination of foil, etc., may be provided on the outer surface of the pan. This may further improve the appearance of the finished product although it is generally unnecessary. Various adhesives, laminating agents and coating agents may be used as those skilled in the art will readily understand. Obviously, the adhesive and the laminating agent must be of such character as to be capable of resisting baking temperatures and at present a large number of such substances is available on the market.

Referring now more particularly to the drawing, a preferred embodiment of the invention will be described.

Fi 1 illustrates a blank constituted of a suitable cellulosic material such as cardboard of a generally circular shape and denoted by reference character In. Blank I0 is provided with score lines H defining a hexagon-shaped area [2 which subsequently is going to form the bottom wall of the finished pan. Further score lines IS in parallel-spaced position with respect to score lines II are provided and define together With score lines ll side walls 9 of the finished mm. It will be noted in Fig. 1 that score lines 13 do not meet with each other but end at score lines l4 and I5 respectively forming a generally V-shaped configuration at each corner of bottom wall l2. The angle enclosed by score lines It and I5 depends on the slop which is desired to be imparted to the finished pan. This angle is the greater the greater the desired slope of the finished pan. In addition to score lines [4 and I5, radially disposed score lines 5 are provided in each V-shaped pair of score lines bisecting the angle therebetween.

After the blank has been properly scored in accordance with the arrangement shown in Fig. 1, it may be readily converted into the erected form illustrated in Fig. 2. The necessary folding operations may be accomplished by mean of hand manipulations although, of course, in most cases it will be preferred to employ suitable tools or folding devices for obtaining the desired result. In fact, in some cases it is possible to dispense with some or all of the score lines shown in Fig. 1 and to rely on suitable folding members or jaws to fold the mawrial into the desired position. One practical method which was found satisfactory included pinching the material of the blank within the space defined by the divergent score lines I l and I to bring lines l4 and [5 into closely adjacent position and to cause the production of a fold or pleat which takes up the excess material defined by said score lines. This pleat ll (Figs. 2 and 4) may then be folded into the plane of flange I8 which comprises the portions of the circular blank defined by score lines I3 and the terminal portions of score lines It and I5. It is preferred to bend the flange portions into a position in which they are substantially parallel with bottom wall I2.

After the blank has been shaped and folded into the desired polygonal form illustrated in Fig. 2, it may be permanently retained in shape by means of suitable fastening elements I9. These fastening elements may be in the simplest case metallic staples bonding certain portions of the flanges or inserted in the pleats ll underneath the flange. The latter procedure is generally preferred since it prevents the possibility of contact of the baked product with the staple. It is also possible, however, to use a textile thread stitched around the circumference of the flange or a suitable adhesive capable of resisting baking temperatures without deteriorating or softening.

The physical appearance of pleats I! will be best observed in Fig. 4 which is an enlarged fragmentary view illustrating the underside of the bakin pan of the invention. As it has been pointed out in the foregoing, the sheet-like material of the pan is preferabl laminated with a metallic foil or the like as this is clearly shown in Fig. 3. It will be observed that a metal foil, preferably aluminum, 20 is laminated or otherwise secured to cellulosic base 2|. A similar lamination or its equivalent may be provided on the bottom surface of the pan.

Blank [0 has been described in the foregoing as of a generally circular shape. In case the circumference of the blank is a perfect circle, the formation of pleats l'I will slightly distort the circular shape. This may be compensated for, if desired, by providing corresponding protruding portions in the regions of the blank which are subsequently forming the pleats. In most cases, however, the distortion is slight enough to be disregarded and does not require such corrective measures.

Fig. 5 illustrates a portion of a modified blank Illa which is in most respects similar to theone shown, in Fig. 1 and includes score lines H-a, l3-a, l5-a and l6--a corresponding to score lines ll, [3, l5 and IS in Fig. 1. The difference resides in the omission of score lines M. This will cause but little change in the finished product and will merely cause that the side wall. adjoining pleat I! from the side where score line l4 was omitted, will form a continuous and unbroken surface including the underside of the pleat (see Fig. 4). The result is a somewhat stronger and more rigid structure.

It will be noted that the baking pan of the invention provides a number of important advantages. First of all, as a result of its polygonal shape, both the bottom wall and all of the side walls of more or less sloping character are completely plane surfaces. Thus, curved surfaces are completely absent from the novel structure of the invention and a completely smooth and plane inner surface is assured which provides ideal conditions for baking and causes the production of an attractive, tasty crust.

It is also to be observed that the pan of the invention is integrally formed from a single sheet of material by means of folding operations and without expensive moulding or pressure drawing operations. As is known, folding, if properly carried out, preserves the originally smooth surface of the material and avoids the danger of the formation of detrimental wrinkles and other defects which were inseparable from prior singleuse pans made by drawin processes. Thus, due to the presence of completely smooth inner surfaces the pie will not adhere to the inner surface of the pan but may be readily removed therefrom either integrally or by portions without injuring the delicate and flaky crust.

Moreover, due to the polygonal shape of the baking pan of the invention, the finished bakery product, pie or cake, may be readily cut into pieces or segments of uniform size. Furthermore, it will be noted that the pan employing the invention is extremely simple in structure and inexpensive to manufacture so that it may be discarded after a single use. Thus, for the first time in the history of the art a completely satisfactory single-use baking utensil has been provided having superior properties and permitting to bake, transport and to sell the bakery product, particularly pies, in the same receptacle.

Although the present invention has been described in connection with a preferred embodiment thereof, variations and modifications may be resorted to by those skilled in the art without departing from the principles of the present invention. Thus, while a baking pan of hexagonal shape has been illustrated, square, pentagonal, octagonal and similar regular or even irregularshaped pans may be made. I consider all of these variations and modifications as within the true spirit and scope of my invention as disclosed in the foregoing description and defined by the appended claims.

I claim: 1. The method of making shallow plates from sheets which comprises providing an integral blank of sheet-like cellulosic blank, folding said blank along a plurality of lines to form a hexagonal fiat bottom panel, upwardly sloping side walls constituted of a plurality of plane side panels, and a circular flat marginal flange having a hexagonal inner edge, and folding the excess material between said side panels into closed pleats whereby a plate having an inner surface constituted of plane surfaces is obtained.

2. The method of making shallow plates from sheets which comprises providing an integral blank of sheet-like fibrous cellulosic material having a generally circular shape, scoring said circular blank along a plurality of straight lines to define a hexagonal bottom wall panel, a plurality of side wall panels and triangular areas between adjoining side wall panels, and folding said scored blank to form a plate having a plane bottom wall surrounded by sloping plane side walls terminating at the top thereof in a continuous flat circular marginal flange having a hexagonal inner edge and having a closed pleat in each corner of said side walls constituted of said triangular areas.

HARRY F. WATERS. 

